1. Field of the Invention
The present invention relates generally to power supplies, and more particularly, to power supplies for projectiles fired by gun, mortars and the like, which generate power due to an acceleration of the projectile.
2. Prior Art
All existing and future smart and guided projectiles and those with means of one-way or two-way communications with a command or tracking station or with each other require electric power for their operation. In addition, as munitions are equipped with the means of communicating their type and characteristics with the firing system to ensure that the intended round is being used and for fire control purposes, and for health monitoring and diagnostics runs before loading, they would require a low level of power supply minutes and sometimes even seconds before being loaded into the gun system. The amount of power required for the proper operation of such smart and guided munitions or those equipped with the aforementioned health monitoring and diagnostics capabilities, is dependent on their mode of operation and the on-board devices that have to be powered. The amount of power requirement is fairly small if the projectile is required to only receive a RF or other similar signal and to power sensors such as MEMs types of accelerometers and rate gyros or health monitoring and diagnostics related electronics. The power requirement is increased if the projectile is also required to communicate back to the ground or some mobile station. The power requirement, however, becomes significant when the projectile has to be equipped with electric or smart materials based actuation devices for guidance and control, particularly if the projectile is required to become highly maneuverable over long traveling times and while traveling at relatively high speeds such as supersonic speeds.
In addition, all existing and future smart and guided projectiles are preferably equipped with means for sensing one or preferably more of the firing setback and set-forward accelerations, radial accelerations, flight vibration in the longitudinal and lateral (radial) directions, and terminal point impact induced acceleration. The measurements preferably include the related acceleration profiles. The sensory information can be used for guidance and control purposes as well as for fuze safety and operation.
The mass-spring systems used in the piezoelectric based power generators described in the U.S. Pat. Nos. 7,231,874 and 7,312,557, the contents of which are incorporated herein by reference, can generally be used in the construction of the disclosed integrated power generators and inertial sensors of the present invention for gun-fired munitions.